This February, on the third anniversary of the fitness guru's disappearance, a podcast called Missing Richard Simmons appeared online.

Five episodes later, the podcast has become an international hit.

The New York Times has called it "morally suspect." But the world is taken by Simmons' story: Why would a major celebrity, accustomed to the spotlight and committed to his fans, choose to abruptly disappear?

In reality, Simmons hasn't disappeared; he's withdrawn from public life, and from his friends as well. He's ghosting just about everyone, prompting wild speculation about his health, his mental state, and even his liberty.

While there's evidence that Richard Simmons is actually doing this of his own volition, he has chosen not to explain his decision — beyond a brief phone interview he granted to the Today show a year ago.

"I just sort of wanted to be a little bit of a loner for a little while,'' Simmons told Savannah Guthrie on Today. "I've taught like, thousands and thousands of classes, and you know, right now I just want to sort of take care of me."

That brief interview is the only thing the public has heard from Richard Simmons in three years. And his statement was likely compelled by an investigative piece published two days earlier by Andy Martino, then a reporter at The New York Daily News.

On Day 6, Martino told me he was shocked by the level of interest in his story.

"I certainly had no idea that it was going to be... the most-read piece that I've written to date, and probably will ever write," he said.

"I think that there's a connection that people feel to him as someone who seemed to be really earnest and how much he cared for people."

"So there's a certain sense of feeling and sympathy."

Richard Simmons, in his signature shorts and tanktop, leads Capitol Hill staff and visitors through an exercise routine in Washington, D.C. Simmons has given most of his life to helping people overcome weight issues. (TIM SLOAN/AFP/Getty Images)

A sudden silence

That's certainly Dan Taberski's take on Simmons. Taberski is a documentary filmmaker, a comedy writer and the creator and host of Missing Richard Simmons. He considers Simmons a friend.

In the first episode of Missing Richard Simmons, Taberski explains the podcast's motive and why he's determined to connect with the missing star.

"I think he's important — so much more so than his goofball public persona lets on," Taberski says. "And also, because a lot of people who know him and whose lives have been changed by him [are] worried, or angry, or full of grief."

Dan Taberski, host of the "Missing Richard Simmons" podcast posted this photo of himself and Simmons on Instagram in 2012. (Instagram/Dan Taberski)

Martino heard from those people too. He told me about meeting friends of Simmons who couldn't understand why their super-empathetic friend would freeze them out.

"I found a group of friends in Los Angeles who were very worried about Simmons... several of whom had gone to his house, [but] were turned away by his housekeeper."

Teresa Reveles, described by Taberski as Simmons' "housekeeper-slash-best friend," is a suspect figure in some of the more conspiratorial theories around Simmons.

Allegations that she is controlling the star have been flatly denied by his management.

Martino included some of those accusations in his story. He told me that he tried to contact Reveles for comment, but received no response.

So he went to the residence.

"I spent as much time outside that gate as I could trying to talk to both Simmons and Teresa and just didn't have any success with anybody emerging from that house. And I don't believe she's spoken to any media or done anything publicly."

Richard Simmons attends the 87th Annual Macy's Thanksgiving Day Parade on November 28, 2013 in New York City. (Laura Cavanaugh/Getty Images)

If Simmons had opted for a different communication strategy, it's possible the suspicions around his disappearance may have been more easily dispelled.

But the lack of any response invited speculation — and drove both Martino and Taberski to stake out the home of a person who almost certainly wants no contact with the public.

In Missing Richard Simmons, Taberski suggests that Simmons' silence is so out of character that it proves there's something wrong.

"Richard Simmons completely and inexplicably stopped being Richard Simmons," he says. "And I want to find out why."

One of Simmons' friends expressed a similar view in Martino's article, saying, "If Richard never comes out of the shadows and says he is OK, then no one will ever know the truth."

"I mean, if the question is: Is somebody who is mentally unwell being harassed by this attention? I would certainly hope not."- Andy Martino

An ethical conundrum

Framing the Simmons' disappearance as a mystery to be solved has made Taberski's podcast a hit. But what if he doesn't want to be investigated?

The backlash to Taberski's inquiry includes not only this article from The New York Times, but also articles from publications like Wired, which calls it "icky," and The Guardian, which asks if the hit podcast is "an elaborate stalking stunt."

I asked Andy Martino for his opinion on why the only statement Simmons has made — the interview he gave to the Today show after Martino's article was published — wasn't enough for Taberski and others.

Martino told me that none of his original sources had been reassured by Simmons' statement.

Richard Simmons, before he retreated from public life. ((Tina Fineberg/Associated Press))

"Some of the people who spoke to me on background were happy to simply hear his voice, but nobody thought he sounded happy."

Martino, who has appeared on Taberski's podcast, said that if Simmons is dealing with a mental health issue, it is vital that inquiry doesn't become harassment.

"If the question is: is somebody who is mentally unwell being harassed by this attention? I would certainly hope not."

But Martino believes there's no malevolence in Taberski's motives.

"I think he's doing it with his heart in the right place."

"If you were interviewing close friends of Richard Simmons who have known him for decades, they would say 'OK, fine, but please, Richard: just drop us a quick line and tell us you're OK, because we love you; we care about you.'"

The final episode of Missing Richard Simmons drops next week.

To hear my conversation with Andy Martino, download our podcast or click the 'Listen' button at the top of this page.